Today was dominated by a hot and humid atmosphere! Dewpoints were in the upper 60s and lower 70s, creating a heat index close to 100 degrees across eastern Oklahoma. This time of the year it can be very difficult to get a cold front to provide widespread showers and storms; however, locally, we have mountain ranges that tend to help in the development of thunderstorms if you can get convergence. Take a look at the picture above by 40/29 storm chaser Brian Emfinger.

Convergence takes place when two opposite winds come together to lift air parcels; moreover, mountainous terrain can act like a ramp in order to lift the air high into the upper levels of the troposphere.


The dominant surface wind flow today was out of the south. This morning, a complex of showers and storms died out to our west, leaving a cool outflow boundary that moved over eastern Oklahoma and western Arkansas. This outflow boundary met up with a southerly surface wind creating showers and storms, and interestingly enough, the storms formed over the terrain of the area, but why?

Warm air aloft was running around 10 degree Celsius, creating a bit of cap across the River Valley, so weak convergence and convection wasn't enough to develop storms; however, there was enough forcing along the mountains to beat the cap, and form showers and storms. We'll continue to see this pattern over the next couple of days before a cold front moves in for the weekend!